Moisture-retentive cooling gel, moisture-retentive cooling gel laminate, and moisture-retentive cooling plaster

ABSTRACT

The present invention provides a moisture-retentive cooling gel, a laminate thereof, and a moisture-retentive cooling plaster, which offer moisture-retaining and cooling effects for a controlled duration and have superior functionality, e.g., capability of delivering and transporting an effective ingredient such as a pharmacological active ingredient, a perfume or a deodorant. The moisture-retentive cooling gel comprises: a water-retentive matrix (a1) of a water-soluble polymer having a water content of not lower than 40 wt %; and fibers (f) dispersed in the water-retentive matrix, the fibers (f) having a hydrophilic property at least at surfaces thereof, some of the fibers (f) being exposed on a surface of the water-retentive matrix (a1). The gel has a higher water content and a higher water vaporization rate. An endothermally water-dissolvable compound may be retained in the water-retentive matrix and/or the fibers for enhancement of the cooling capacity of the gel. The gel may be formed into a single gel layer or into a plurality of gel layers which are stacked one on another with a mesh sheet interposed therebetween for provision of the gel laminate. Further, the gel layer or the gel laminate may be provided on an air-permeable support sheet for provision of the plaster.

This is a division of application Ser. No. 09/301,599 filed Apr. 29,1999. Now U.S. Pat. No. 6,335,088.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a moisture-retentive cooling get, alaminate thereof, and a moisture-retentive cooling plaster using such agel or laminate.

2. Description of Related Art

Moisture-retentive cooling plasters have been known which include asupport base and a gel layer such as of a water-soluble polymer providedon the support base. Such a moisture-retentive cooling plaster issuperior in portability and adhesion, and used as a cooling medium fortreatment of a feverish patient instead of an ice pack and an icepillow.

The moisture-retentive cooling plaster, if its portability is anessential requirement, has a smaller water content because the size ofthe gel layer provided on the support base is limited. This leads to ashorter duration of moisture-retaining and cooling effects.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a moisture-retentivecooling gel, a laminate thereof, and a moisture-retentive coolingplaster, which offer moisture-retaining and cooling effects for acontrolled duration and have superior functionality, e.g., capability ofdelivering and transporting an effective ingredient such as apharmacological active ingredient or a perfume.

In accordance with a first aspect of the present invention, there isprovided a moisture-retentive cooling gel which comprises: awater-retentive matrix of a water-soluble polymer having a water contentof not lower than 40 wt %; and fibers dispersed in the water-retentivematrix, the fibers having a hydrophilic property at least at surfacesthereof, some of the fibers being exposed on a surface of thewater-retentive matrix.

In accordance with a second aspect of the present invention, there isprovided a moisture-retentive cooling gel laminate which comprises aplurality of layers of the aforesaid moisture-retentive cooling gelstacked one on another with a mesh sheet or a porous sheet interposedtherebetween.

In accordance with a third aspect of the present invention, there isprovided a moisture-retentive cooling plaster which comprises: anair-permeable support sheet; and the aforesaid moisture-retentivecooling gel or the aforesaid moisture-retentive cooling gel laminateprovided on the support sheet.

The moisture-retentive cooling gel, the moisture-retentive cooling gellaminate and the moisture-retentive cooling plaster in accordance withthe present invention each have a greater water content and a higherwater vaporization rate and, therefore, sustainably offer superioreffects when used as: (1) a medical cooling pad for cooling a part of afeverish human body; (2) a cooling package for fresh protection of fish,drinking water, liquor and the like in transportation thereof; (3) acooling sheet for prevention of melting of chocolate in transportationthereof; (4) a pad for muscle cooling after sport and for skin careafter sunburn; (5) a protective pad for water supply to a dry skin; and(6) a plaster containing an anti-inflammatory agent.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a sectional view schematically illustrating amoisture-retentive cooling gel according to Example 1 of the presentinvention;

FIG. 2 is a sectional view schematically illustrating amoisture-retentive cooling gel according to Example 2 of the presentinvention;

FIG. 3 is a sectional view schematically illustrating amoisture-retentive cooling gel according to Example 4 of the presentinvention;

FIG. 4 is a sectional view schematically illustrating amoisture-retentive cooling gel according to Example 5 of the presentinvention;

FIG. 5 is a sectional view schematically illustrating amoisture-retentive cooling gel according to Example 7 of the presentinvention;

FIG. 6 is a sectional view schematically illustrating amoisture-retentive cooling gel according to Example 8 of the presentinvention;

FIG. 7 is a sectional view schematically illustrating amoisture-retentive cooling gel laminate according to Example 9 of thepresent invention;

FIG. 8 is a sectional view schematically illustrating amoisture-retentive cooling gel laminate according to Example 11 of thepresent invention;

FIG. 9 is a sectional view schematically illustrating amoisture-retentive cooling gel laminate according to Example 12 of thepresent invention;

FIG. 10 is a perspective view illustrating separately packaged compoundsof the gel laminate of FIG. 9; and

FIG. 11 is a sectional view schematically illustrating amoisture-retentive cooling plaster according to Example 14 of thepresent invention;

DETAILED DESCRIPTION OF THE INVENTION

In accordance with the present invention, there are provided: amoisture-retentive cooling gel (A1, A2) which comprises awater-retentive matrix of a water-soluble polymer having a water contentof not lower than 40 wt %, and fibers (f) dispersed in thewater-retentive matrix, the fibers having a hydrophilic property atleast at surfaces thereof, at least some of the fibers being exposed ona surface of the water-retentive matrix; a moisture-retentive coolinggel (A3, A4) which comprises a water-retentive matrix of a water-solublepolymer having a water content of not lower than 40 wt %, and awater-absorbing polymer filler (v1, v11, v12, v13) dispersed in thewater-retentive matrix, at least some of the water-absorbing polymerfiller being exposed on a surface of the water-retentive matrix; and amoisture-retentive cooling gel (A5, A6) which comprises awater-retentive matrix of a water-soluble polymer having a water contentof not lower than 40 wt %, a water-absorbing polymer filler (v1, v11,v12, v13, v2) and fibers (f) having a hydrophilic property at least atsurfaces thereof, the water-absorbing polymer filler and the fibersbeing dispersed in the water-retentive matrix, at least some of thewater-absorbing polymer filler and the fibers being exposed on a surfaceof the water-retentive matrix.

Examples of the fibers (f) having a hydrophilic property at least attheir surfaces include pulp fibers, cotton fibers, rayon fibers, andother hydrophilic resin fibers, and hydrophobic resin fibers, glassfibers and ceramic fibers which have been surface-treated to be impartedwith a hydrophilic property, but not limited thereto.

The fibers (f) are dispersed in the water-retentive matrix, preferablyin such a manner that the fibers (f) are three-dimensionally entangledwith each other.

The fibers (f) may preliminarily be impregnated with water and thendispersed in the water-retentive matrix. Thus, the gel to be finallyobtained has a higher water content because the water retained in thefibers (f) can additionally be incorporated in the gel. This isadvantageous for enhancement of the moisture-retaining and coolingeffects.

Usable as the water-absorbing polymer filler (v1, v2) in the presentinvention are highly water-absorbing polymer fillers capable ofabsorbing water of a weight about 200 to 1000 times the original weight.

The water-absorbing polymer filler is preferably in a particulate orfibrous form, but the form thereof is not limited thereto. Theparticulate form herein includes a pellet form and a powdery form.

Where a particulate water-absorbing polymer filler (hereinafter referredto as “water-absorbing polymer particles (v1)”) is used, it is preferredthat the water-absorbing polymer particles (v1) are in contact with eachother in the water-retentive matrix and some of the polymer particlesare exposed on a surface of the water-retentive matrix.

Preferred examples of the water-absorbing polymer particles (v1) includehighly water-absorbing polymer particles available under the trade namesof SUNWET IM-300 and SUNWET IM-1000 from Sanyo Chemical Industry Co.,Ltd., and under the trade name of AQUAKEEP from Sumitomo Seika Co.,Ltd., but not limited thereto.

Usable as the fibrous water-absorbing polymer filler (hereinafterreferred to as “water-absorbing polymer fibers (v2)”) are highlywater-absorbing and highly hygroscopic fibers such as BELL OASIS (tradename) available from Kanebo Gosen Co., Ltd.

Examples of the water-soluble polymer to be used for the water-retentivematrix in the present invention include polyacrylic acid and saltsthereof, gelatin, polyvinyl alcohol, sodium carboxymethylcellulose,carrageenan, sodium alginate and carboxyvinyl polymers. Thesewater-soluble polymers may be used alone. For enhancement ofwater-retentive, moisture-retentive and adhesive properties of thematrix, however, it is preferred to use a mixture of plural polymersselected from these polymers. A preferred water-soluble polymer mixtureis, for example, a mixture of sodium polyacrylate, polyvinyl alcohol,gelatin and carrageenan, but not limited thereto.

Where the mixture of sodium polyacrylate, polyvinyl alcohol, gelatin andcarrageenan is used as the water-soluble polymer in the presentinvention, for example, the blending ratio of the total weight ofpolyvinyl alcohol and sodium polyacrylate to the total weight of gelatinand carrageenan is preferably 1:1 to 5:1, and polyvinyl alcohol andsodium polyacrylate are typically present in a proportion of 0.1 to 25wt %, preferably 1 to 15 wt %, more preferably 3 to 12 wt %, mostpreferably 5 to 10 wt %, based on the weight of the water-solublepolymer mixture. The blending weight ratio of sodium polyacrylate topolyvinyl alcohol is preferably 0.5:1 to 20:1.

In the present invention, an endothermally water-dissolvable compoundmay optionally be retained in the water-retentive matrix. Theendothermally water-dissolvable compound may be in a solid form or in aliquid form. In view of the production process and the duration of thecooling effect, the former is more preferred.

The endothermally water-dissolvable compound is preferably contained inthe water-soluble polymer forming the water-retentive matrix, but may beretained in the water-retentive matrix in any other manner. For example,the compound is retained in either or both of the fibers having ahydrophilic property at least at their surfaces and the water-absorbingpolymer filler.

Examples of the endothermally water-dissolvable compound include ureaand sodium nitrate, which may be used either alone or in combination.

Where the endothermally water-dissolvable compound is blended in thewater-retentive matrix, the blending ratio of the compound is typically0.1 to 25 wt %, preferably 0.5 to 20 wt %, more preferably 0.5 to 15 wt%, based on the weight of the water-retentive matrix.

In the present invention, the water-retentive matrix typically has a pHwithin a range between 4 and 10, preferably between 5 and 9. A pH rangebetween 6 and 8 is more preferred because the resultingmoisture-retentive cooling gel provides a cold feeling to skin and arefreshing feeling after removal of the gel.

A lower alcohol is preferably added to the water-retentive matrix topromote water vaporization for enhancement of the cooling effect and forextension of the duration of the cooling effect. Examples of the loweralcohol include methyl alcohol, ethyl alcohol and propyl alcohol, butnot limited thereto. Any of alcohols which are miscible with water andhave a lower boiling point than water to form an azeotrope with watermay be used. Any of known humectants such as glycerol and polyethyleneglycol may optionally be blended in the water-retentive matrix.

In the present invention, it is preferred to add a water-solublepharmacological active ingredient to at least one of the water-retentivematrix and the water-absorbing polymer filler. This allows fortransportation, delivery and release of the pharmacological activeingredient with water migration in the gel.

Examples of the water-soluble pharmacological active ingredient includedipotassium glycyrrhetinate, water-soluble azulene and acrinol.

In accordance with the present invention, there are also provided: amoisture-retentive cooling gel laminate (A7, A8) which comprises a meshsheet (n1) and a plurality of layers of any of the aforesaidmoisture-retentive cooling gels stacked one on another with the meshsheet interposed therebetween; and a moisture-retentive cooling gellaminate (A9) which comprises a porous sheet (n2) and a plurality oflayers of any of the aforesaid moisture-retentive cooling gels stackedone on another with the porous sheet interposed therebetween.

Usable as the mesh sheet (n1) for the gel laminate (A7, A8) of thepresent invention are any mesh sheets having opposite surfaces ontowhich the gel layers can adhere to be fixed thereon. The mesh sheet (n1)per se preferably has water-absorbing, water-retentive andwater-permeable properties. Preferred examples of the mesh sheet includepaper sheets, fabric sheets and relatively coarse nonwoven fabric sheetscomposed of hydrophilic and/or water-absorbing polymer fibers, but notlimited thereto. The water-absorbing polymer fibers stated earlier as anexample of the fibrous water-absorbing polymer filler (v2) arepreferably used as the water-absorbing polymer fibers for the nonwovenfabric sheets.

Where the mesh sheet (n1) is composed of the polymer fibers, the meshsheet is preferably chemically or physically surface-treated so as to beable to offer an anchoring effect to the water-retentive matrix. Thus,the gel layers can firmly be bonded and fixed onto the opposite sides ofthe sheet (n1) for provision of the multi-layer gel laminate.

For the chemical surface treatment, a proper surfactant, for example,may be used to impart the surfaces of the polymer fibers with ahydrophilic property. Where the sheet is subjected to the chemicalsurface treatment, it is preferred not to impair the water-retentive andwater-permeable properties of the sheet. For the physical surfacetreatment, a needling process, for example, is employed to fuzz theopposite surfaces of the mesh sheet.

Preferably, the mesh sheet (n1) is preliminarily impregnated with water.Thus, the water content of the entire gel laminate is increased therebyto contribute to extension of the duration of the moisture-retaining andcooling effects.

The mesh sheet (n1) may also retain an endothermally water-dissolvablecompound. This is preferred because an endothermic dissolution processoccurs on interfaces between the mesh sheet and the gel layers toenhance the cooling effect. Examples of the endothermallywater-dissolvable compound include those previously described.

The porous sheet (n2) to be used for the gel laminate (A9) of thepresent invention is composed of a flexible material. Examples thereofinclude open-cell foamed resin sheets, among which urethane foam sheetsare preferred, but not limited thereto.

The porous sheet (n2) may also retain an endothermally water-dissolvablecompound. In this case, any of the aforesaid-endothermallywater-dissolvable compounds may be retained in cells of the porous sheet(n2).

In the present invention, the mesh sheet (n1) or the porous sheet (n2)retaining therein the aforesaid compound is prepared separately from theaforesaid gel layers and, when required, the gel layers are stacked onthe sheet for formation of the gel laminate. This is preferred becausethe endothermic dissolution process can more effectively be utilized.

In accordance with the present invention, there is also provided amoisture-retentive cooling plaster (A10) which comprises anair-permeable support sheet (1), and any of the aforesaidmoisture-retentive cooling gels or any of the aforesaidmoisture-retentive cooling gel laminates provided on the support sheet.

In the plaster (B) of the present invention, any of air-permeablesupport sheets known in the art may be used on an “as is” basis as theair-permeable support sheet (1) which supports the gel or the gellaminate.

In the present invention, for ease of handling of the moisture-retentivecooling gels, the moisture-retentive cooling gel laminates and themoisture-retentive cooling plaster, at least one exposed surface thereofis preferably covered with a liner (p).

In the case of the gel of the present invention which includes thefibers (f) dispersed in the water-retentive matrix, the water containedin the water-retentive matrix easily migrates through the hydrophilicsurfaces of the fibers (f) within the matrix. In addition, at least someof the fibers (f) are exposed on the surface of the water-retentivematrix, so that the water can easily be vaporized through the exposedfibers. Therefore, the rate of the water vaporization from thewater-retentive matrix increases for enhancement of the cooling capacityof the gel.

In the case of the gel which includes the water-absorbing polymer filler(v1, v2) dispersed in the water-retentive matrix, the water contained inthe water-retentive matrix is attracted to the water-absorbing polymerfiller (v1, v2) and easily migrates through the surface and innerportions of the water-absorbing polymer filler within the matrix. Inaddition, at least some of the water-absorbing polymer filler (v1, v2)is exposed on the surface of the water-retentive matrix, so that thewater can easily be vaporized through the exposed polymer filler.Therefore, the rate of the water vaporization from the water-retentivematrix increases for enhancement of the cooling capacity of the gel.

Further, the water absorbed by the water-absorbing polymer filler (v1,v2) is additionally incorporated in the water-retentive matrix, so thatthe gel has a greater water content.

In the case of the gel which includes the water-absorbing polymer filler(v1, v2) and the surface-hydrophilic fibers (f) dispersed in thewater-retentive matrix, the water contained in the water-retentivematrix more easily migrates through the surface and inner portions ofthe water-absorbing polymer filler (v1, v2) and the hydrophilic surfacesof the fibers (f) within the matrix. In addition, at least some of thewater-absorbing polymer filler (v1, v2) or the fibers (f) are exposed onthe surface of the water-retentive matrix, so that the water can easilybe vaporized through the exposed filler or fibers. Therefore, the rateof the water vaporization from the water-retentive matrix increases forenhancement of the cooling capacity of the gel.

Further, the water absorbed by the water-absorbing polymer filler (v1,v2) is additionally incorporated in the water-retentive matrix, so thatthe gel has a greater water content.

In the present invention, the fibers (f) and/or the water-absorbingpolymer filler (v1, v2) dispersed in the water-retentive matrix have agood affinity for the matrix because of their surface properties, andfunction like reinforcement materials. Thus, the water-retentive matrix,even if having a greater volume, is free from tearing and rupture withan excellent shape retention property. Therefore, the volume of thewater-retentive matrix can be increased, while the shape retentionproperty of the matrix is ensured. Accordingly, the duration of themoisture-retaining and cooling effects of the gel can be extended byincreasing the volume of the matrix.

In the case of the gel laminate of the present invention which includesa plurality of layers of the moisture-retentive cooling gel stacked oneon another with the mesh sheet (n1) or the porous sheet (n2) interposedtherebetween, the water content and water vaporization rate thereof candrastically be increased or properly controlled by properly determiningthe number of the gel layers to be used. In addition, water or aningredient can be retained in the mesh sheet (n1) or the porous sheet(n2) so as to be incorporated in the gel laminate. Where the mesh sheet(n1) and the porous sheet (n2) are composed of a water-absorbingpolymer, the water content and the amount of the ingredient to beretained therein can properly be controlled.

In the case of the gel laminate which includes the porous sheet (n2)retaining the endothermally water-dissolvable compound and the pluralityof gel layers stacked one on another with the porous sheet interposedtherebetween, the gel layers may be prepared separately from the poroussheet and, when the laminate is to be used, stacked one on another withthe porous sheet interposed therebetween. Thus, the starting point,duration and rate of the endothermic dissolution process can becontrolled as desired.

The present invention will hereinafter be described in detail by way ofexamples thereof. It should be understood that the invention be notlimited to these examples.

EXAMPLES Example 1

A moisture-retentive cooling gel (A1) of Example 1 was prepared in thefollowing manner.

First, the following ingredients were blended for preparation of awater-retentive matrix of the moisture-retentive cooling gel (A1).

Sodium polyacrylate 4 g Gelatin 1 g Polyvinyl alcohol 2 g Glycerol 18 gSodium carboxymethylcellulose 1 g Carrageenan 2 g Ethyl alcohol 1 gParaben 0.1 g Water 70.9 g 100.0 g

A pulp suspension was prepared in such an amount that the ratio of thepulp suspension to the water-retentive matrix was 1:10 on a dry weightbasis.

The water-retentive matrix and the pulp suspension were blended in thefollowing manner for preparation of a moisture-retentive cooling gelcomposition.

(1) Gelatin and carrageenan were dissolved in 20 g of water withheating.

(2) Polyvinyl alcohol was dissolved in 20 g of water with heating.

(3) The solutions obtained in the steps (1) and (2) were fully mixedwith each other with stirring.

(4) Sodium polyacrylate and sodium carboxymethyl-cellulose were mixedwith glycerol.

(5) The mixture obtained in the step (4) and the solution obtained inthe step (3) were added to and mixed with the remaining ingredients withstirring, and the pulp suspension was further added to and fully mixedwith the resulting mixture with stirring. Thus, the gel composition in aslurry form was prepared.

The moisture-retentive cooling gel (A1) of Example 1 which was comprisedof a planar gel layer (a1) and had a sectional configuration as shown inFIG. 1 was prepared from the gel composition slurry thus prepared. Morespecifically, the gel composition slurry was spread in an amount ofabout 200 to 3000 g/m² on a polypropylene liner (p) for formation of theplanar gel layer (a1), and another polypropylene liner (p) was appliedonto the gel layer.

In the moisture-retentive cooling gel (A1) thus obtained, pulp fibers(f) were virtually homogeneously dispersed in the gel layer (a1), andentangled with each other to form a three-dimensional network. Some ofthe fibers (f) were exposed on the surfaces of the gel layer.

The moisture-retentive cooling gel (A1) in which water retained in thefibers (f) was also incorporated had a water content of about 65 to 85wt % based on the total weight of the gel layer at maximum. Thus, thewater content of the gel was remarkably increased, compared with theconventional one. Further, it was possible to form the gel compositionslurry into the relatively thick planar gel layer (a1), which wasstrengthened by the fibers (f).

After the liner (p) was removed, the exposed surface of the planar gellayer (al) of the moisture-retentive cooling gel (A1) had a sufficientadhesiveness to skin and the like. With the gel applied onto the skin,water easily migrated within the gel layer (a1), and easily vaporizedfrom the gel layer at a higher water vaporization rate. This is becausethe fibers (f) dispersed to form a fiber network in the gel layer (a1)functioned like water channels, and some of the fibers (f) were exposedon the surface of the gel layer (a1)

The moisture-retentive cooling gel (A1) of Example 1 had a higher watercontent, and water channels opening to the atmosphere were formed in thegel layer (al) by the network of the three-dimensionally entangledfibers (f). Therefore, the moisture-retaining and cooling capacitiesthereof were remarkably increased.

Example 2

A moisture-retentive cooling gel (A2) of Example 2 was prepared in thefollowing manner.

First, the following ingredients were blended for preparation of awater-retentive matrix of the moisture-retentive cooling gel.

Sodium polyacrylate 6 g Gelatin 2 g Polyvinyl alcohol 3 g Glycerol 18 gSodium carboxymethylcellulose 2 g Carrageenan 1 g Ethyl alcohol 1 gCrystalline urea 5 g Water 62 g 100 g

A pulp suspension was prepared in such an amount that the ratio of thepulp suspension to the water-retentive matrix was 1:10 on a dry weightbasis.

The water-retentive matrix and the pulp suspension were blended in thefollowing manner for preparation of a moisture-retentive cooling gelcomposition.

(1) Gelatin and carrageenan were dissolved in 20 g of water withheating.

(2) Polyvinyl alcohol was dissolved in 20 g of water with heating.

(3) Sodium polyacrylate and sodium carboxymethyl-cellulose were mixedwith glycerol.

(4) The solution obtained in the step (2) was added to and fully mixedwith the solution obtained in the step (1) with stirring.

(5) The mixture obtained in the step (3) and the solution obtained inthe step (4) were added to and mixed with the remaining ingredients, andthe pulp suspension was further added to and fully mixed with theresulting mixture with stirring.

(6) Crystalline urea was added to the mixture obtained in the step (5)and homogeneously dispersed therein with stirring. Thus, a gelcomposition in a slurry form was prepared.

The moisture-retentive cooling gel (A2) of Example 2 which included aplanar gel layer (a2) and had a sectional configuration as shown in FIG.2 was prepared in the same manner as in Example 1 from the gelcomposition slurry thus prepared.

The moisture-retentive cooling gel (A2) of Example 2 offered the sameeffects as the gel of Example 1. In addition, the gel (A2) had a highercooling capacity because of the endothermic effect of the crystallineurea (s) retained in the water-retentive matrix.

Example 3

A moisture-retentive cooling gel of Example 3 was prepared insubstantially the same manner as in Example 2, except that crystallinesodium nitrate instead of the crystalline urea was blended in the gelcomposition slurry so as to be dispersed in a solid form in the gellayer. It is noted that the construction of the gel of Example 3 is notshown.

The moisture-retentive cooling gel of Example 3 maintained its highcooling capacity for an extended period, because the crystalline sodiumnitrate incorporated in the gel layer was gradually dissolved in thewater within the gel layer to sustain the endothermic process.

Example 4

A moisture-retentive cooling gel of Example 4 was prepared insubstantially the same manner as in Example 2, except that crystallineammonium nitrate instead of the crystalline urea was blended in the gelcomposition slurry so as to be dispersed in a solid form in the gellayer. It is noted that the construction of the gel of Example 4 is notshown.

The moisture-retentive cooling gel of Example 4 maintained its highcooling capacity for an extended period, because the crystallineammonium nitrate incorporated in the gel layer was gradually dissolvedin the water within the gel layer to sustain the endothermic process.

Example 5

A moisture-retentive matrix of the same formulation as in Example 2 wasemployed for preparation of a gel composition slurry for amoisture-retentive cooling gel (A3) of Example 5.

Water-absorbing polymer pellets (AQUAKEEP available from Sumitomo SeikaCo., Ltd.) were prepared, and 10 g of water was completely impregnatedinto 0.2 g of the water-absorbing polymer pellets (water-retentivematrix:water-absorbing polymer pellets=400:1 on a dry weight basis).

The water-retentive matrix and the water-absorbing polymer pelletsimpregnated with water were blended in the following manner forpreparation of the moisture-retentive cooling gel composition.

(1) Gelatin was dissolved in 20 g of water with heating.

(2) Polyvinyl alcohol was dissolved in 20 g of water with heating.

(3) Sodium polyacrylate and sodium carboxymethyl-cellulose were mixedwith glycerol.

(4) The solution obtained in the step (2) was added to and fully mixedwith the solution obtained in the step (1) with stirring.

(5) The mixture obtained in the step (3) and the solution obtained inthe step (4) were added to and mixed with the remaining ingredients withstirring. Then, crystalline urea and the water-absorbing polymer pellets(v1) impregnated with water were added to and fully mixed with theresulting mixture with stirring. Thus, the gel composition slurry wasprepared.

The moisture-retentive cooling gel (A3) of Example 5 which included aplanar gel layer (a3) and had a sectional configuration as shown in FIG.3 was prepared in the same manner as in Example 1 from the gelcomposition slurry thus prepared.

As shown, the moisture-retentive cooling gel (A3) had such a structurethat the water-absorbing polymer pellets (v1) were virtually in contactwith one another for formation of three-dimensional linkage in the gellayer (a3) and some of the polymer pellets were exposed on surfaces ofthe gel layer.

The moisture-retentive cooling gel (A3) as a whole retained a fargreater amount of water than the conventional one, because the waterabsorbed by the water-absorbing polymer pellets (v1) was added to thewater contained in the water-retentive matrix.

The water-absorbing polymer pellets (v1) dispersed in the gel layer (a3)served as a reinforcement filler, so that the gel layer had a muchhigher strength. This permits the gel layer to have a much greaterthickness.

The linkage of the water-absorbing polymer pellets (v1) in the gel layer(a3) functioned like water channels. Therefore, the water retained inthe water-retentive matrix was attracted to the water-absorbing polymerpellets (v1), and vaporized through the water-absorbing polymer pellets,being released outside the gel. Thus, the water migration was promotedwith a very high water vaporization rate.

Example 6

A moisture-retentive cooling gel (A4) of Example 6 which included aplanar gel layer (a4) and had a sectional configuration as shown in FIG.4 was prepared in substantially the same manner as in Example 5, exceptthat water-absorbing polymer pellets were divided into three groups(v11, v12, v13) which were distinguished by different colors (e.g., red,blue and yellow) and respectively impregnated with the followingpharmacological active ingredients (i.e., three differentpharmacological active ingredients).

RED No. 2, BLUE No. 1 and YELLOW No. 4 dyes were used for the colordistinction of the three groups of water-absorbing polymer pellets.Then, 1% aqueous solutions of the three water-soluble pharmacologicalactive ingredients (acrinol, water-soluble azulene and dipotassiumglycyrrhetinate, hereinafter referred to simply as “pharmacologicalsolutions”) were prepared, and the water-absorbing polymer pellets (v11,v12, v13) distinguished by the three different colors were respectivelyimpregnated with 10 g of the ingredients.

The moisture-retentive cooling gel (A4) thus obtained offeredmoisture-retentive and cooling effects equivalent to those offered bythe gel of Example 5. In addition, the pharmacological ingredientsrespectively retained in the water-absorbing polymer pellets (v11, v12,v13) distinguished by the different colors were gradually released intothe water-retentive matrix in the gel layer (a4), and migrate throughthe linkage of the water-absorbing polymer pellets (v11, v12, v13) ordiffused into the gel layer toward a surface of the gel layer.

Thus, pharmacological activities were effected on the surface of the gellayer. Further, the water-absorbing polymer pellets distinguished by theplural colors made the gel layer colorful and allowed for easyconfirmation of the types of the pharmacological ingredientsincorporated therein.

Example 7

A moisture-retentive cooling gel of Example 7 was prepared insubstantially the same manner as in Example 6, except that a perfume wasused instead of one of the pharmacological solutions and impregnatedinto one of the three groups of water-absorbing polymer pelletsdistinguished by the different colors. It is noted that the constructionof the gel of Example 7 is not shown.

The moisture-retentive cooling gel of Example 7 offered substantiallythe same effects as the gel (A4) In addition, the perfume was stablyretained in the gel layer, so that the perfume and water were vaporizedto waft fragrance for an extended period.

Example 8

For preparation of a moisture-retentive cooling gel (A5) of Example 8, awater-retentive matrix of the same formulation as in Example 5 wasprepared. A pulp suspension was prepared in such an amount that theratio of the water-retentive matrix to the pulp suspension was 10:1 on adry weight basis, as in Example 1. Then, a gel composition slurry wasprepared in the same manner as in Example 1. Three pharmacologicalsolutions were respectively impregnated into three groups ofwater-absorbing polymer pellets (v11, v12, v13) distinguished by threedifferent colors, as in Example 6. Then, the water-absorbing polymerpellets (v11, v12, v13) were mixed with the gel composition slurry.Thus, the moisture-retentive cooling gel (A5) of Example 8 whichincluded a planar gel layer (a5) and had a sectional configuration asshown in FIG. 5 was prepared.

In the moisture-retentive cooling gel (A5) thus prepared,three-dimensional water channels were more effectively formed in the gellayer (a5) than in the moisture-retentive cooling gel (A4) of Example 6.This is because pulp fibers (f) were three-dimensionally dispersed incontact with the water-absorbing polymer pellets (v11, v12, v13) withinthe gel layer (a5). Therefore, the moisture-retentive cooling gel (A5)was very useful with a higher cooling capacity than the gel of Example 6and with the capability of diffusing the pharmacological activeingredients.

Example 9

For preparation of a moisture-retentive cooling gel (A6) of Example 9, awater-retentive matrix of the same formulation as in Example 2 and apulp suspension were prepared.

Highly water-absorbing and highly hygroscopic fibers available under thetrade name of BELL OASIS from Kanebo Gosen Co., Ltd. were used aswater-absorbing polymer fibers (v2). A pharmacological solution wasprepared by dissolving 0.05 g of dipotassium glycyrrhetinate as apharmacological active ingredient in 30 g of water, and then impregnatedinto 3 g of the water-absorbing polymer fibers (v2) (water-retentivematrix:water-absorbing polymer fibers=10:1 on a dry weight basis).

A gel composition slurry was prepared in the same manner as in Example 6by blending the water-retentive matrix, the pulp suspension and thewater-absorbing polymer fibers (v2) impregnated with the pharmacologicalsolution.

The moisture-retentive cooling gel (A6) of Example 9 which included aplanar gel layer (a6) and had a sectional configuration as shown in FIG.6 was prepared in the same manner as in Example 1 from the gelcomposition slurry thus prepared.

Since water channels were three-dimensionally densely formed by thewater-absorbing polymer fibers (v2) and pulp fibers (f) in the gel layer(a6) of the moisture-retentive cooling gel (A6), water migration in thegel layer (a6) was easier. In addition, dipotassium glycyrrhetinateimpregnated in the water-absorbing polymer fibers (v2) was easilytransported in the gel layer (a6) by the water migration thereby to beefficiently delivered to an intended surface of the gel layer.

Example 10

A moisture-retentive cooling gel laminate (A7) of Example 10 which has asectional configuration as shown in FIG. 7 has a two-layer structureincluding a first gel layer (a71) and a second gel layer (a72) which arestacked one on the other with a mesh sheet (n1) interposed therebetween,and held between upper and lower polypropylene liners (p, p).

The first gel layer (a71) is composed of a gel composition slurry of thesame formulation as in Example 1, and the second gel layer (a72) iscomposed of a gel composition slurry of the same formulation as inExample 5.

The mesh sheet (n1) is a water-permeable and hydrophilic coarse nonwovenfabric composed of polyester fibers and rayon fibers blended in a ratioof 1:1 and entangled with each other. The mesh sheet (n1) ispreliminarily subjected to a needling process so that opposite surfacesthereof are fuzzed.

In the two-layered moisture-retentive cooling gel laminate (A7), waterchannels are formed in the first gel layer (a71) by pulp fibers. In thesecond gel layer (a72), water channels are formed by water-absorbingpolymer pellets in contact with each other, and a greater amount ofwater retained in the water-absorbing polymer pellets is incorporated.

In addition, the first and second gel layers (a71, a72) are firmlybonded to the water-permeable and hydrophilic mesh sheet (n1) with somefibers of the fuzzed mesh sheet (n1) protruding into the respective gellayers. Water channels are also formed by these fibers.

Thus, the moisture-retentive cooling gel laminate (A7) has a higherwater content and a higher water vaporization rate thereby to maintain ahigh cooling capacity for a long period.

Example 11

A moisture-retentive cooling gel laminate of Example 11 hassubstantially the same construction as the gel laminate of Example 10,except that the following mesh sheet is employed.

The mesh sheet employed in Example 11 is composed of highlywater-absorbing and hygroscopic polymer fibers available under the tradename of BELL OASIS which were employed in Example 9.

The gel laminate offers more excellent effects than the gel laminate ofExample 10. This is because a greater amount of water absorbed by themesh sheet is incorporated in the gel laminate, and the mesh sheetprovides water channels between the gel layers of the laminate to allowfor water vaporization and water communication therethrough.

Example 12

A moisture-retentive cooling gel laminate (A8) of Example 12 has asectional configuration as shown in FIG. 8, and includes a first gellayer (a81) and a second gel layer (a82) which are stacked one on theother with a mesh sheet (n1) interposed therebetween and held betweenupper and lower polypropylene liners (p, p).

The first gel layer (a81) is composed of a gel composition slurry of thesame formulation as in Example 5, and the second gel layer (a82) iscomposed of a gel composition slurry of the same formulation as inExample 9. The mesh sheet (n1) is the same as that employed in Example10, and is preliminarily subjected to a needling process so thatopposite surfaces thereof are fuzzed.

In the two-layered moisture-retentive cooling gel laminate (A8), waterchannels are formed in the first gel layer (a81) by the water-absorbingpolymer pellets (v1) in contact with each other, and a greater amount ofwater retained in the polymer pellets (v1) is incorporated in the firstgel layer (a81). In the second gel layer (a82), a greater amount ofwater retained in the water-absorbing polymer fibers (v2) isincorporated, and water channels are formed by the water-absorbingpolymer fibers (v2). In addition, the first and second gel layers (a81,a82) are firmly bonded to the water-permeable and hydrophilic mesh sheet(n1) with some fibers of the fuzzed mesh sheet (n1) protruding into therespective gel layers.

With this arrangement, the water content is drastically increased, andthe water vaporization rate is increased by the formation of the waterchannels in the gel layers. Therefore, the moisture-retentive coolinggel laminate (A8) can maintain a high cooling capacity for an extendedperiod.

Example 13

A moisture-retentive cooling gel laminate (A9) of Example 13 has asectional configuration as shown in FIG. 9, and includes a first gellayer (a91) and a second gel layer (a92) which are stacked one on theother with a porous sheet (n2) interposed therebetween.

The first gel layer (a91) is prepared in the same manner as in Example 6by employing a gel composition slurry of the same formulation as inExample 1 and three groups of water-absorbing polymer pellets (v11, v12,v13) distinguished by three different colors and respectivelyimpregnated with pharmacological solutions as in Example 6.

The second gel layer (a92) is prepared in the same manner as in Example9 by employing a gel composition slurry of the same formulation as inExample 1 and water-absorbing polymer fibers (v2) as employed in Example9.

The porous sheet (n2) is a polyurethane foam sheet containing opencells, in which crystalline sodium nitrate not shown are contained.

The first gel layer (a91) and the second gel layer (a92) which are eachheld between polypropylene liners (p, p), and the porous sheet (n2)retaining sodium nitrate are individually enclosed inmoisture-impermeable film bags (c) in a moisture free state as shown inFIG. 10.

The first and second gel layers (a91, a92) and the porous sheet (n2)thus individually enclosed are taken out of the film bags (c) whenrequired. Then, the first gel layer (a91) and the second gel layer (a92)with one-side liners (p, p) removed therefrom are respectively bondedonto upper and lower surfaces of the porous sheet (n2), and pressedagainst the porous sheet (n2) from the other-side liners (p, p) byfingers, so that surface portions thereof are squeezed into the poroussheet (n2). Thus, the gel laminate (A9) having the construction shown inFIG. 9 is obtained.

As described above, the gel laminate (A9) can easily be produced, whenneeded, by combining the first and second gel layers (a91, a92) with theporous sheet (n2). In the gel laminate (A9) thus produced, thecrystalline sodium nitrate retained in the porous sheet (n2) isdissolved in water contained in the water-retentive matrix immediatelyafter being brought into contact with the water-retentive matrixsqueezed into cells of the porous sheet (n2), thereby starting theendothermic process to enhance the cooling effect.

The gel laminate (A9) can be produced in situ when needed, so that theendothermic process of dissolution of the crystalline sodium nitrate canbe started at the use of the gel laminate. Therefore, the endothermicprocess can effectively be utilized for a long period. In addition, thefirst gel layer (a91) and the second gel layer (a92) offer the sameeffects as the gel layers of the examples described above.

Example 14

A moisture-retentive cooling gel laminate of Example 14 hassubstantially the same construction as the gel laminate of Example 13,except that a mesh sheet composed of pulp fibers is used instead of theporous sheet. In is noted that the construction of the gel laminate ofExample 14 is not shown.

In the gel laminate of Example 14, crystalline sodium nitrate isretained in the mesh sheet composed of the pulp fibers. Therefore, whenthe first and second gel layers are bonded on opposite surfaces of themesh sheet, water retained in the respective gel layers is introducedinto the sheet through the pulp fibers, so that the endothermic-processis promptly started over the entire sheet. Thus, a greater coolingeffect can promptly be obtained.

Example 15

A moisture-retentive cooling plaster can be obtained by providing any ofthe moisture-retentive cooling gels of Examples 1 to 9 or any of themoisture-retentive cooling gel laminates of Examples 10 to 14 on anair-permeable support sheet.

A moisture-retentive cooling plaster (B) employing the gel laminate ofExample 12 is shown in FIG. 11 as one typical example. In FIG. 11, thereare shown the air-permeable support sheet (1), the moisture-retentivecooling gel laminate (A10) and a propylene liner (p).

The air-permeable support sheet (1) is, for example, an open cellpolyester-urethane foam sheet having a thickness of 1.5 mm, a cellnumber of 13±3 cells/25 mm, a tensile strength of not lower than 0.7kg/cm, an extensibility of not lower than 100% and a density of 30±5kg/m².

Such a plaster advantageously enjoys the effects offered by the gellaminate as well as effects offered by the support sheet. Morespecifically, the plaster is highly flexible and does not burden asurface on which the plaster is applied. In addition, the support sheetof the plaster is excellent in printability, so that an illustration, atrade mark and letters can clearly be printed on the support sheet.

As can be understood from the examples described above, themoisture-retentive cooling gels according to the present invention eachhave a higher moisture-retention capacity because the water-retentivematrix is capable of retaining a greater amount of water.

Where the fibers are dispersed in the water-retentive matrix, the fibersensure easy water migration within the matrix and easy watervaporization from the matrix, thereby ensuring a higher coolingcapacity.

Further, the fibers dispersed in the water-retentive matrix have a goodaffinity for the matrix because of the hydrophilic property imparted tothe surfaces of the fibers, and function like a reinforcement material.Therefore, the water-retentive matrix has a superior shape-retentionproperty, so that the volume of the water-retentive matrix can beincreased. This allows the gels to retain a greater amount of water,making the moisture-retaining and cooling effects thereof sustainable.

Where the water-absorbing polymer filler (particles or fibers) isdispersed in the water-retentive matrix, the water content of thewater-retentive matrix is remarkably increased, and water channels areformed in the water-retentive matrix by the linkage of thewater-absorbing polymer particles or fibers. This increases the watermigration rate and the water vaporization amount, thereby increasing thecooling capacity.

Moreover, a water-soluble pharmacological active ingredient retained inthe water-absorbing polymer filler can be incorporated in thewater-retentive matrix, and transported within the matrix. Further, aplurality of pharmacological active ingredients and/or a perfume and/ora deodorant can be retained in plural groups of water-absorbing polymerparticles distinguished by different colors. Thus, the gels are mademore functional.

The water channels are stably formed by the water-absorbing polymerfiller in the water-retentive matrix, thereby remarkably improving thecapacity for transporting the pharmacological active ingredients, aperfume, a deodorant and water.

Further, the liners provided on the gels ensure easy handling.

In the moisture-retentive cooling gel laminate according to the presentinvention, the plurality of gel layers are stacked one on another withthe mesh sheet or the porous sheet interposed therebetween, so that thetotal thickness of the gel layers can be increased. Therefore, the watercontent can be increased to improve the cooling capacity and themoisture-retention capacity. Further, the water content of the gellaminate can drastically be increased by increasing the number of thegel layers, so that the duration of the moisture-retaining and coolingeffects can remarkably be extended. Moreover, the addition of theendothermally water-dissolvable compound further improves the coolingcapacity.

Where the mesh sheet is composed of the water-absorbing polymer fibers,the water content can be increased, and active ingredients such as awater-soluble pharmacological active ingredient, a perfume or adeodorant can be retained in the mesh sheet. Thus, the gel laminate hasmultiple functions.

Further, the gel laminate can be produced when needed by combining thegel layers with the mesh or porous sheet retaining the endothermallywater-dissolvable compound, so that the endothermic process can bestarted upon production of the gel laminate. Thus, the endothermicprocess can effectively be utilized. In addition, the gel laminate has agood portability.

While the present invention has thus been described in detail withreference to specific examples thereof, it should be understood thatthese examples be not limitative of the invention. Various modificationsmay be made without departing from the spirit and scope of the inventionas defined in the appended claims.

What is claimed is:
 1. A moisture-retentive cooling gel laminatecomprising a porous sheet and a plurality of layers of amoisture-retentive cooling gel, said cooling gel comprising: awater-retentive matrix of a water-soluble polymer, the matrix having awater content of not lower than 40 wt %; and fibers dispersed in thewater-retentive matrix, the fibers having a hydrophilic property atleast at surfaces thereof, at least some of the fibers being exposed ona surface of the water-retentive matrix, the plurality of gel layersbeing stacked one on another with the mesh sheet interposedtherebetween.
 2. A moisture-retentive cooling gel laminate as set forthin claim 1, wherein the mesh sheet contains an endothermallywater-dissolvable compound.
 3. A moisture-retentive cooling gel laminateas set forth in claim 1, wherein the mesh sheet consists of a fibrouswater-absorbing polymer.
 4. A moisture-retentive cooling gel laminate asset forth in claim 1, wherein the water-absorbing polymer fillercontains at least one compound selected from the group consisting of awater-soluble pharmacological active ingredient, a perfume and adeodorant.
 5. A moisture-retentive cooling gel laminate as set forth inclaim 1, which is formed into a planer layer having opposite surfaces onat least one of which is covered with a liner.
 6. A moisture-retentivecooling plaster comprising a moisture-retentive cooling gel laminate asrecited in claim 1 and an air-permeable support sheet, themoisture-retentive cooling gel laminate being supported on the supportsheet.
 7. A moisture-retentive cooling plaster as set forth in claim 6,wherein the air-permeable support sheet contains an endothermallywater-dissolvable compound.
 8. A moisture-retentive cooling plaster asset forth in claim 6, wherein the laminate is formed into a planer layerhaving opposite surfaces on at least one of which is covered with aliner.
 9. A moisture-retentive cooling gel laminate comprising a meshsheet, a layer of a moisture-retentive cooling gel, said cooling gelcomprising: a water-retentive matrix of a water-soluble polymer, thematrix having a water content of not lower than 40 wt %; and fibersdispersed in the water-retentive matrix, the fibers having a hydrophilicproperty at least at surfaces thereof, at least some of the fibers beingexposed on a surface of the water-retentive matrix; and a layer of anendothermic gel, the endothermic gel comprising a water-retentive matrixof a water-soluble polymer having a water content of not lower than 40wt % and an endothermally water-dissolvable compound, themoisture-retentive cooling gel layer and the endothermic gel layer beingstacked one on the other with the mesh sheet interposed therebetween.10. A moisture-retentive cooling gel laminate as set forth in claim 9,wherein the mesh sheet contains an endothermally water-dissolvablecompound.
 11. A moisture-retentive cooling gel laminate as set forth inclaim 9, wherein the mesh sheet consists of a fibrous water-absorbingpolymer.
 12. A moisture-retentive cooling gel laminate as set forth inclaim 9, wherein the water-absorbing polymer filler contains at leastone compound selected from the group consisting of a water-solublepharmacological active ingredient, a perfume and a deodorant.
 13. Amoisture-retentive cooling gel laminate as set forth in claim 9, whichis formed into a planer layer having opposite surfaces on at least oneof which is covered with a liner.
 14. A moisture-retentive coolingplaster comprising a moisture-retentive cooling gel laminate as recitedin claim 9 and an air-permeable support sheet, the moisture-retentivecooling gel laminate being supported on the support sheet.
 15. Amoisture-retentive cooling plaster as set forth in claim 14, wherein theair-permeable support sheet contains an endothermally water-dissolvablecompound.
 16. A moisture-retentive cooling plaster as set forth in claim14, wherein the laminate is formed into a planer layer having oppositesurfaces on at least one of which is covered with a liner.
 17. Amoisture-retentive cooling gel laminate comprising a porous sheet and aplurality of layers of a moisture-retentive cooling gel, said coolinggel comprising: a water-retentive matrix of a water-soluble polymer, thematrix having a water content of not lower than 40 wt %; and fibersdispersed in the water-retentive matrix, the fibers having a hydrophilicproperty at least at surfaces thereof, at least some of the fibers beingexposed on a surface of the water-retentive matrix; the plurality of gellayers being stacked one on another with the porous sheet interposedtherebetween.
 18. A moisture-retentive cooling gel laminate as set forthin claim 17, wherein the porous sheet contains an endothermallywater-dissolvable compound.
 19. A moisture-retentive cooling gellaminate as set forth in claim 17, wherein the porous sheet consists ofa polyurethane foam sheet containing open cells.
 20. Amoisture-retentive cooling gel laminate as set forth in claim 17,wherein the water-absorbing polymer filler contains at least onecompound selected from the group consisting of a water-solublepharmacological active ingredient, a perfume and a deodorant.
 21. Amoisture-retentive cooling gel laminate as set forth in claim 17, whichis formed into a planer layer having opposite surfaces on at least oneof which is covered with a liner.
 22. A moisture-retentive coolingplaster comprising a moisture-retentive cooling gel laminate as recitedin claim 17 and an air-permeable support sheet, the moisture-retentivecooling gel laminate being supported on the support sheet.
 23. Amoisture-retentive cooling plaster as set forth in claim 22, wherein theair-permeable support sheet contains an endothermally water-dissolvablecompound.
 24. A moisture-retentive cooling plaster as set forth in claim22, wherein the laminate is formed into a planer layer having oppositesurfaces on at least one of which is covered with a liner.
 25. Amoisture-retentive cooling gel laminate comprising a porous sheet, alayer of a moisture-retentive cooling gel, said cooling gel comprising:a water-retentive matrix of a water-soluble polymer, the matrix having awater content of not lower than 40 wt %; and fibers dispersed in thewater-retentive matrix, the fibers having a hydrophilic property atleast at surfaces thereof, at least some of the fibers being exposed ona surface of the water-retentive matrix; and a layer of an endothermicgel, the endothermic gel comprising a water-retentive matrix of awater-soluble polymer having a water content of not lower than 40 wt %and an endothermally water-dissolvable compound, the moisture-retentivecooling gel layer and the endothermic gel layer being stacked one on theother with the porous sheet interposed therebetween.
 26. Amoisture-retentive cooling gel laminate as set forth in claim 25,wherein the porous sheet contains an endothermally water-dissolvablecompound.
 27. A moisture-retentive cooling gel laminate as set forth inclaim 25, wherein the porous sheet consists of a polyurethane foam sheetcontaining open cells.
 28. A moisture-retentive cooling gel laminate asset-forth in claim 25, wherein the water-absorbing polymer fillercontains at least one compound selected from the group consisting of awater-soluble pharmacological active ingredient, a perfume and adeodorant.
 29. A moisture-retentive cooling gel laminate as set forth inclaim 25, which is formed into a planer layer having opposite surfaceson at least one of which is covered with a liner.
 30. Amoisture-retentive cooling plaster comprising a moisture-retentivecooling gel laminate as recited in claim 25 and an air-permeable supportsheet, the moisture-retentive cooling gel laminate being supported onthe support sheet.
 31. A moisture-retentive cooling plaster as set forthin claim 30, wherein the air-permeable support sheet contains anendothermally water-dissolvable compound.
 32. A moisture-retentivecooling plaster as set forth in claim 31, wherein the laminate is formedinto a planer layer having opposite surfaces on at least one of which iscovered with a liner.
 33. A moisture-retentive cooling plastercomprising a moisture-retentive cooling gel, said cooling gelcomprising: a water-retentive matrix of a water-soluble polymer, thematrix having a water content of not lower than 40 wt %; and fibersdispersed in the water-retentive matrix, the fibers having a hydrophilicproperty at least at surfaces thereof, at least some of the fibers beingexposed on a surface of the water-retentive matrix; and an air-permeablesupport sheet, the moisture-retentive cooling gel being supported on thesupport sheet.
 34. A moisture-retentive cooling plaster as set forth inclaim 33, wherein the air-permeable support sheet contains anendothermally water-dissolvable compound.
 35. A moisture-retentivecooling plaster as set forth in claim 33, wherein the gel is formed intoa planer layer having opposite surfaces on at least one of which iscovered with a liner.
 36. A moisture-retentive cooling gel laminatecomprising a mesh sheet and a plurality of layers of amoisture-retentive cooling gel, said cooling gel comprising: awater-retentive matrix of a water-soluble polymer, said matrix having awater content of not lower than 40 wt %; and a water-absorbing polymerfiller dispersed in the water-retentive matrix; at least one of thewater-absorbing polymer filler being exposed on a surface of thewater-retentive matrix; the plurality of gel layers being stacked one onanother with the mesh sheet interposed therebetween.
 37. Amoisture-retentive cooling gel laminate as set forth in claim 36,wherein the mesh sheet contains an endothermally water-dissolvablecompound.
 38. A moisture-retentive cooling gel laminate as set forth inclaim 36, wherein the mesh sheet consists of a fibrous water-absorbingpolymer.
 39. A moisture-retentive cooling gel laminate as set forth inclaim 36, wherein the water-absorbing polymer filler contains at leastone compound selected from the group consisting of a water-solublepharmacological active ingredient, a perfume and a deodorant.
 40. Amoisture-retentive cooling gel laminate as set forth in claim 36, whichis formed into a planer layer having opposite surfaces on at least oneof which is covered with a liner.
 41. A moisture-retentive coolingplaster comprising a moisture-retentive cooling gel laminate as recitedin claim 36, and an air-permeable support sheet, the moisture-retentivecooling gel laminate being supported on the support sheet.
 42. Amoisture-retentive cooling plaster as set forth in claim 41, wherein theair-permeable support sheet contains an endothermally water-dissolvablecompound.
 43. A moisture-retentive cooling plaster as set forth in claim41, wherein the laminate is formed into a planer layer having oppositesurfaces on at least one of which is covered with a liner.
 44. Amoisture-retentive cooling gel laminate comprising a mesh sheet, a layerof a moisture-retentive cooling gel, said cooling gel comprising: awater-retentive matrix of a water-soluble polymer, said matrix having awater content of not lower than 40 wt %; and a water-absorbing polymerfiller dispersed in the water-retentive matrix, at least one of thewater-absorbing polymer filler being exposed on a surface of thewater-retentive matrix; and a layer of an endothermic gel, theendothermic gel comprising a water-retentive matrix of a water-solublepolymer having a water content of not lower than 40 wt % and anendothermally water-dissolvable compound, the moisture-retentive coolinggel layer and the endothermic gel layer being stacked one on the otherwith the mesh sheet interposed therebetween.
 45. A moisture-retentivecooling gel laminate as set forth in claim 44, wherein the mesh sheetcontains an endothermally water-dissolvable compound.
 46. Amoisture-retentive cooling gel laminate as set forth in claim 44,wherein the mesh sheet consists of a fibrous water-absorbing polymer.47. A moisture-retentive cooling gel laminate as set forth in claim 44,wherein the water-absorbing polymer filler contains at least onecompound selected from the group consisting of a water-solublepharmacological active ingredient, a perfume and a deodorant.
 48. Amoisture-retentive cooling gel laminate as set forth in claim 44, whichis formed into a planer layer having opposite surfaces on at least oneof which is covered with a liner.
 49. A moisture-retentive coolingplaster comprising a moisture-retentive cooling gel laminate as recitedin claim 44, and air-permeable support sheet, the moisture-retentivecooling gel laminate being supported on the support sheet.
 50. Amoisture-retentive cooling plaster as set forth in claim 49, wherein theair-permeable support sheet contains an endothermally water-dissolvablecompound.
 51. A moisture-retentive cooling plaster as set forth in claim49, wherein the laminate is formed into a planer layer having oppositesurfaces on at least one of which is covered with a liner.
 52. Amoisture-retentive cooling gel laminate comprising a porous sheet aplurality of layers of a moisture-retentive cooling gel, said coolinggel comprising: a water-retentive matrix of a water-soluble polymer,said matrix having a water content of not lower than 40 wt %; and awater-absorbing polymer filler dispersed in the water-retentive matrix,at least one of the water-absorbing polymer filler being exposed on asurface of the water-retentive matrix, the plurality of gel layers beingstacked one on another with the porous sheet interposed therebetween.53. A moisture-retentive cooling gel laminate as set forth in claim 52,wherein the porous sheet contains an endothermally water-dissolvablecompound.
 54. A moisture-retentive cooling gel laminate as set forth inclaim 52, wherein the porous sheet consists of a polyurethane foam sheetcontaining open cells.
 55. A moisture-retentive cooling gel laminate asset forth in claim 52, wherein the water-absorbing polymer fillercontains at least one compound selected from the group consisting of awater-soluble pharmacological active ingredient, a perfume and adeodorant.
 56. A moisture-retentive cooling gel laminate as set forth inclaim 52, which is formed into a planer layer having opposite surfaceson at least one of which is covered with a liner.
 57. Amoisture-retentive cooling gel laminate as set forth in claim 52, whichis formed into a planer layer having opposite surfaces on at least oneof which is covered with a liner.
 58. A moisture-retentive coolingplaster comprising a moisture-retentive cooling gel laminate as recitedin claim 52 and an air-permeable support sheet, the moisture-retentivecooling gel laminate being supported on the support sheet.
 59. Amoisture-retentive cooling plaster as set forth in claim 58, wherein theair-permeable support sheet contains an endothermally water-dissolvablecompound.
 60. A moisture-retentive cooling plaster as set forth in claim58, wherein the laminate is formed into a planer layer having oppositesurfaces on at least one of which is covered with a liner.
 61. Amoisture-retentive cooling gel laminate comprising a porous sheet, alayer of a moisture-retentive cooling gel, said cooling gel comprising:a water-retentive matrix of a water-soluble polymer, said matrix havinga water content of not lower than 40 wt %; and a water-absorbing polymerfiller dispersed in the water-retentive matrix, at least one of thewater-absorbing polymer filler being exposed on a surface of thewater-retentive matrix; and a layer of an endothermic gel, theendothermic gel comprising a water-retentive matrix of a water-solublepolymer having a water content of not lower than 40 wt % and anendothermally water-dissolvable compound, the moisture-retentive coolinggel layer and the endothermic gel layer being stacked one on the otherwith the porous sheet interposed therebetween.
 62. A moisture-retentivecooling gel laminate as set forth in claim 61, wherein the porous sheetcontains an endothermally water-dissolvable compound.
 63. Amoisture-retentive cooling gel laminate as set forth in claim 61,wherein the porous sheet consists of a polyurethane foam sheetcontaining open cells.
 64. A moisture-retentive cooling gel laminate asset forth in claim 61, wherein the water-absorbing polymer fillercontains at least one compound selected from the group consisting of awater-soluble pharmacological active ingredient, a perfume and adeodorant.
 65. A moisture-retentive cooling plaster comprising amoisture-retentive cooling gel laminate as recited in claim 61 and anair-permeable support sheet, the moisture-retentive cooling gel laminatebeing supported on the support sheet.
 66. A moisture-retentive coolingplaster as set forth in claim 65, wherein the air-permeable supportsheet contains an endothermally water-dissolvable compound.
 67. Amoisture-retentive cooling plaster as set forth claim 66,wherein thelaminate is formed into a planer layer having opposite surfaces on atleast one of which is covered with a liner.
 68. A moisture-retentivecooling plaster comprising a moisture-retentive cooling gel, saidcooling gel comprising: a water-retentive matrix of a water-solublepolymer, said matrix having a water content of not lower than 40 wt %;and a water-absorbing polymer filler dispersed in the water-retentivematrix, at least one of the water-absorbing polymer filler being exposedon a surface of the water-retentive matrix; and an air-permeable supportsheet, the moisture-retentive cooling gel being supported on the supportsheet.
 69. A moisture-retentive cooling plaster as set forth in claim68, wherein the air-permeable support sheet contains an endothermallywater-dissolvable compound.
 70. A moisture-retentive cooling plaster asset forth in claim 68, wherein the gel is formed into a planer layerhaving opposite surfaces on at least one of which is covered with aliner.
 71. A moisture-retentive cooling gel laminate comprising a meshsheet as plurality of layers of a moisture-retentive cooling gel, saidcooling gel comprising: a water-retentive matrix of a water-solublepolymer, said matrix having a water content of not lower than 40 wt %;and a water-absorbing polymer filler and fibers dispersed in thewater-retentive matrix, the fibers having a hydrophilic property atleast at surfaces thereof, at least some of the water-absorbing polymerfiller and the fibers being exposed on a surface of the water-retentivematrix; the plurality of gel layers being stacked one on another withthe mesh sheet interposed therebetween.
 72. A moisture-retentive coolinggel laminate as set forth in claim 71, wherein the mesh sheet retains anendothermally water-dissolvable compound.
 73. A moisture-retentivecooling gel laminate as set forth in claim 71, wherein the mesh sheetconsists of a fibrous water-absorbing polymer.
 74. A moisture-retentivecooling gel laminate as set forth in claim 71, wherein thewater-absorbing polymer filler contains at least one compound selectedfrom the group consisting of a water-soluble pharmacological activeingredient, a perfume and a deodorant.
 75. A moisture-retentive coolinggel laminate as set forth in claim 71, which is formed into a planerlayer having opposite surfaces on at least one of which is covered witha liner.
 76. A moisture-retentive cooling plaster comprising amoisture-retentive cooling gel laminate as recited in claim 71 and anair-permeable support sheet, the moisture-retentive cooling gel laminatebeing supported on the support sheet.
 77. A moisture-retentive coolingplaster as set forth in claim 76, wherein the air-permeable supportsheet contains an endothermally water-dissolvable compound.
 78. Amoisture-retentive cooling plaster as set forth in claim 76, wherein thelaminate is formed into a planer layer having opposite surfaces on atleast one of which is covered with a liner.
 79. A moisture-retentivecooling gel laminate comprising a mesh sheet, a layer of amoisture-retentive cooling gel, said cooling gel comprising: awater-retentive matrix of a water-soluble polymer, said matrix having awater content of not lower than 40 wt %; and a water-absorbing polymerfiller and fibers dispersed in the water-retentive matrix; the fibershaving a hydrophilic property at least at surfaces thereof, at leastsome of the water-absorbing polymer filler and the fibers being exposedon a surface of the water-retentive matrix; and a layer of anendothermic gel, the endothermic gel comprising a water-retentive matrixof a water-soluble polymer having a water content of not lower than 40wt % and an endothermally water-dissolvable compound, themoisture-retentive cooling gel layer and the endothermic gel layer beingstacked one on the other with the mesh sheet interposed therebetween.80. A moisture-retentive cooling gel laminate as set forth in claim 79,wherein the mesh sheet contains an endothermally water-dissolvablecompound.
 81. A moisture-retentive cooling gel laminate as set forth inclaim 79, wherein the mesh sheet consists of a fibrous water-absorbingpolymer.
 82. A moisture-retentive cooling gel laminate as set forth inclaim 79, wherein the water-absorbing polymer filler contains at leastone compound selected from the group consisting of a water-solublepharmacological active ingredient, a perfume and a deodorant.
 83. Amoisture-retentive cooling gel laminate as set forth in claim 79, whichis formed into a planer layer having opposite surfaces on at least oneof which is covered with a liner.
 84. A moisture-retentive coolingplaster comprising a moisture-retentive cooling gel laminate as recitedin claim 79, an air-permeable support sheet, the moisture-retentivecooling gel laminate being supported on the support sheet.
 85. Amoisture-retentive cooling plaster as set forth in claim 84, wherein theair-permeable support sheet retains an endothermally water-dissolvablecompound.
 86. A moisture-retentive cooling plaster as set forth in claim84, wherein the laminate is formed into a planer layer having oppositesurfaces on at least one of which is covered with a liner.
 87. Amoisture-retentive cooling gel laminate comprising a porous sheet aplurality of layers of a moisture-retentive cooling gel, said coolinggel comprising: a water-retentive matrix of a water-soluble polymer,said matrix having a water content of not lower than 40 wt %; and awater-absorbing polymer filler and fibers dispersed in thewater-retentive matrix, the fibers having a hydrophilic property atleast at surfaces thereof, at least some of the water-absorbing polymerfiller and the fibers being exposed on a surface of the water-retentivematrix; the plurality of gel layers being stacked one on another withthe porous sheet interposed therebetween.
 88. A moisture-retentivecooling gel laminate as set forth in claim 87, wherein the porous sheetcontains an endothermally water-dissolvable compound.
 89. Amoisture-retentive cooling gel laminate as set forth in claim 87,wherein the porous sheet consists of a polyurethane foam sheetcontaining open cells.
 90. A moisture-retentive cooling gel laminate asset forth in claim 87, wherein the water-absorbing polymer fillercontains at least one compound selected from the group consisting of awater-soluble pharmacological active ingredient, a perfume and adeodorant.
 91. A moisture-retentive cooling gel laminate as set forth inclaim 87, which is formed into a planer layer having opposite surfaceson at least one of which is covered with a liner.
 92. Amoisture-retentive plaster comprising a moisture-retentive cooling gellaminate as recited in claim 87 an air-permeable support sheet, themoisture-retentive cooling gel laminate being supported on the supportsheet.
 93. A moisture-retentive cooling plaster as set forth in claim92, wherein the air-permeable support sheet contains an endothermallywater-dissolvable compound.
 94. A moisture-retentive cooling plaster asset forth in claim 92, wherein the laminate is formed into a planerlayer having opposite surfaces on at least one of which is covered witha liner.
 95. A moisture-retentive cooling gel laminate comprising aporous sheet, a layer of a moisture-retentive cooling gel, said coolinggel comprising: a water-retentive matrix of a water-soluble polymer,said matrix having a water content of not lower than 40 wt %; and awater-absorbing polymer filler and fibers dispersed in thewater-retentive matrix, the fibers having a hydrophilic property atleast at surfaces thereof, at least some of the water-absorbing polymerfiller and the fibers being exposed on a surface of the water-retentivematrix; and a layer of an endothermic gel, the endothermic gelcomprising a water-retentive matrix of a water-soluble polymer having awater content of not lower than 40 wt % and an endothermallywater-dissolvable compound, the moisture-retentive cooling gel layer andthe endothermic gel layer being stacked one on the other with the poroussheet interposed therebetween.
 96. A moisture-retentive cooling gellaminate as set forth in claim 95, wherein the porous sheet contains anendothermally water-dissolvable compound.
 97. A moisture-retentivecooling gel laminate as set forth in claim 95, wherein the porous sheetconsists of a polyurethane foam sheet containing open cells.
 98. Amoisture-retentive cooling gel laminate as set forth in claim 95,wherein the water-absorbing polymer filler contains at least onecompound selected from the group consisting of a water-solublepharmacological active ingredient, a perfume and a deodorant.
 99. Amoisture-retentive cooling gel laminate as set forth in claim 95, whichis formed into a planer layer having opposite surfaces on at least oneof which is covered with a liner.
 100. A moisture-retentive coolingplaster comprising a moisture-retentive cooling gel laminate as recitedin claim 95 and an air-permeable support sheet, the moisture-retentivecooling gel laminate being supported on the support sheet.
 101. Amoisture-retentive cooling plaster as set forth in claim 100, whereinthe air-permeable support sheet contains an endothermallywater-dissolvable compound.
 102. A moisture-retentive cooling plaster asset forth in claim 101, wherein the laminate is formed into a planerlayer having opposite surfaces on at least one of which is covered witha liner.
 103. A moisture-retentive cooling plaster comprising amoisture-retentive cooling gel, said cooling gel comprising: awater-retentive matrix of a water-soluble polymer, said matrix having awater content of not lower than 40 wt %; and a water-absorbing polymerfiller and fibers dispersed in the water-retentive matrix, the fibershaving a hydrophilic property at least at surfaces thereof, at leastsome of the water-absorbing polymer filler and the fibers being exposedon a surface of the water-retentive matrix; and an air-permeable supportsheet, the moisture-retentive cooling gel being supported on the supportsheet.
 104. A moisture-retentive cooling plaster as set forth in claim103, wherein the air-permeable support sheet contains an endothermallywater-dissolvable compound.
 105. A moisture-retentive cooling plaster asset forth in claim 103, wherein the gel is formed into a planer layerhaving opposite surfaces on at least one of which is covered with aliner.